<template>
    <div class="cartcontrol">
      <transition name='move'>
         <div class="cart-decrease" v-show="food.count>0" @click="decrease">
          <span class="inner icon-remove_circle_outline"></span>
        </div>
      </transition>
      <div class="cart-count" v-show="food.count>0">{{food.count}}</div>
      <div class="cart-add  icon-add_circle" @click="addCart">
      </div>
    </div>
</template>

<script>
import Vue from 'vue'
export default {
  props:{
    food:{  // 传入商品
      type:Object
    }
  },
  data() {
    return {}
  },
  methods: {
    // 增加按钮
    addCart(event) {
      if(!event._constructed){
        return // 防止PC端执行两次
      }
      if(!this.food.count){ // 如果count不存在,也就是第一次点击
        Vue.set(this.food,'count',1)  //新增加一个不存在的属性需要用set接口才能检测到变化
      }else{
        this.food.count++
      }
       /* 此处派发自定义事件，触发shopcart组件里面的小球动画,并且传入当前点击的元素 */
        this.$emit('add', event.target);
    },
    // 减少按钮
    decrease(){
      if(!event._constructed){
        return 
      }
      if(this.food.count){
        this.food.count--
      }
    }
  }
}
</script>

<style lang="stylus">
  .cartcontrol
    font-size: 0
    .cart-decrease
      display: inline-block
      padding: 6px
      transition: all .4s linear
      opacity: 1
      transform: translate3d(0, 0, 0)
      .inner // 减按钮外层
        display: inline-block
        line-height: 24px
        font-size: 24px
        color: rgb(0, 160, 220)
        transition: all .4s linear
        transform: rotate(0)
      &.move-enter-active, &.move-leave-active
        transition: all 0.4s linear
      &.move-enter, &.move-leave-active
        opacity: 0
        transform: translate3d(24px, 0, 0)
        .inner
          transform: rotate(180deg)
    .cart-count
      display: inline-block
      vertical-align: top
      width: 12px
      padding-top: 6px
      line-height: 24px
      text-align: center
      font-size: 10px
      color: rgb(147, 153, 159)
    .cart-add
      display: inline-block
      padding: 6px
      line-height: 24px
      font-size: 24px
      color: rgb(0, 160, 220)
      
</style>

